1. Field of the Invention
The present invention relates to a vehicle navigation system for guiding a vehicle to a destination. More particularly, the present invention relates to a vehicle-mounted navigation system which enables a driver arbitrarily to set an alternative path for making a detour to thereby avoid a congested road segment. Further, the present invention relates to a recording medium, such as a computer readable medium, having recorded thereon a processing program for use with the vehicle-mounted navigation system.
The present application is based on Japanese Patent Application No. Hei. 11-292540, which is incorporated herein by reference.
2. Description of the Related Art
When a driver considers making a detour from an initially-set route-in order to avoid traffic congestion or to comply with traffic regulations-and searches for an alternative path by using a related vehicle-mounted navigation system (as developed by Yazaki corporation of Japan), the navigation system retrieves a plurality of alternative paths and displays the thus-retrieved alternative paths. The driver then selects a desired one from the alternative paths and drives his car along the thus-selected alternative path.
Retrieval of an alternative path, as performed by the related vehicle-mounted navigation system, will now be described with reference to a flowchart shown in FIG. 7.
As shown in FIG. 7, the related navigation system retrieves an alternative path by the steps of: receiving a detour request from a driver (S701), retrieving a plurality of routes as alternative paths through a detour search operation (S702), displaying the thus-retrieved alternative paths (S703), allowing the driver to select an optimal alternative path (S704), and commencing guidance of a vehicle along the thus-selected alternative path (S705).
Two methods have hitherto been conceived as correction methods when a vehicle deviates from an initially-set route. One method retrieves a new route to the destination by neglecting the initial route, as shown in FIG. 8A. Another method guides the vehicle back to the initially-set route, as shown in FIG. 8B.
The related vehicle-mounted navigation system employs only one or the other of the two above-described correction methods in order to guide a vehicle when the vehicle deviates from an initially-set route.
However, when the related navigation system retrieves an alternative path, it does not allow a driver arbitrarily to set a desired alternative path. Thus, the related vehicle-mounted navigation system cannot retrieve an alternative path that takes into consideration a detour segment desired by the driver. For instance, when a vehicle is driving at a current position S, as shown in FIG. 9, if the driver considers a segment M of an initially-set route R to be non-navigable, for reasons of congestions or traffic regulations, he enters a detour request to the navigation system. Upon receipt of the detour request, the navigation system per se retrieves a plurality of alternative paths, and the driver can select one of those alternative paths.
Perhaps, even when the driver desires to drive his car along a route R1 to make a detour avoiding only a segment M, there is no alternative but to select a route R2 which makes a long detour.
In connection with a method of correcting the course of a vehicle when the vehicle deviates from an initially-set route, a related vehicle-mounted navigation system is provided with only one of the two correction methods: 1) a method of searching for a new route to the destination, as shown in FIG. 8A; and 2) a method of searching for a route which returns the vehicle to the initial route, as shown in FIG. 8B. When a driver desires to use a particular method of searching for a new route, there may be available only a method of searching for a path that returns the vehicle to the initial route. Alternatively, when a driver desires to use one of the two correction methods, depending on his circumstances, only one correction method is available in the related navigation system.
The present invention has been conceived in light of the foregoing circumstance, and is aimed at providing a vehicle-mounted navigation system which enables a user arbitrarily to set an alternative path to avoid a congested road segment. Further, the present invention is aimed at providing a recording medium, such as a computer readable medium, having recorded thereon a processing program for use with the navigation system.
The present invention provides a vehicle-mounted navigation system which detects the current position of a vehicle, searches for a route to a set destination, and guides the vehicle along the thus-retrieved route, the system including:
an input device which enables a user to enter commands;
a detour request receiving device connected to said input device, wherein said detour request receiving device receives a detour request entered from the input device by the user;
a final-point-of-detour receiving device connected to the detour request receiving device, wherein said final-point-of-detour receiving device receives the final point of a segment around which the user requests to make a detour and sets the final point as a final point of detour, after having received the detour request;
an alternative path search device connected to said final-point-of-detour receiving device, wherein said alternative path search device searches for an alternative path interconnecting the current position of the vehicle to the final point of detour, after having received the final point of detour; and
a detour link device which interconnects the final point of the detour to the destination, or to an original route.
According to the present invention, the user can specify the final point of detour and, hence, arbitrarily can set an alternative path.
Preferably, the detour link device further includes:
a detour check device which, by comparison, checks whether or not a match exists between the final point of detour and the original route;
a selection device which, when the detour check device has detected no match, determines whether to search for a new route interconnecting the final point of detour to the destination, or to search for a path which returns the vehicle to the original route, in accordance with settings made by the user;
a new-route search device which, when the selection device has selected to search for a new route to the destination, searches a new route interconnecting the final point of detour to the destination; and
a route return device which, when the selection device has selected return of the vehicle to the original route, searches for a route that returns the vehicle from the final point of detour to the original route.
According to the present invention, the user can determine whether to search for a new route interconnecting the final point of detour to a destination, or to search for a route which returns the vehicle to the original route. The user can set either alternative path in accordance with the user""s desire.
The present invention also provides a vehicle-mounted navigation system which detects the current position of a vehicle, searches for a route to a set destination, and guides the vehicle along the thus-retrieved route, the system including:
a detour check device which, by comparison, checks whether or not a match exists between the final point of detour and the original route;
a selection device which, when the detour check device has detected no match, determines whether to search for a new route interconnecting the final point of detour to the destination, or to search for a path which returns the vehicle to the original route, in accordance with settings made by the user;
a new-route search device which, when the selection device has selected to search for a new route to the destination, searches a new route interconnecting the final point of detour to the destination; and
a route return device which, when the selection device has selected return of the vehicle to the original route, searches for a route that returns the vehicle from the final point of detour to the original route.
According to the present invention, when the vehicle deviates from the original route, the user can determine whether to search for a new route interconnecting the current position to the destination, or to search for a route which returns the vehicle to the original route. The user can set either alternative path in accordance with the user""s desire.
The present invention provides a recording medium, such as a computer readable medium, having recorded thereon a processing program for use with a vehicle-mounted navigation system which detects the current position of a vehicle, searches for a route to a set destination, and guides the vehicle along the thus-retrieved route, the processing program including:
a detour request receiving operation for receiving a detour request entered by a user;
a final-point-of-detour receiving operation which receives, from the detour request receiving operation, a final point of a segment around which the user requests to make a detour, and which sets the final point as a final point of detour;
an alternative path search operation which receives the final point of detour from the final-point-of-detour receiving operation, and which searches for an alternative path interconnecting the current position of the vehicle to the final point of detour, after having received the final point of detour; and
a detour link operation which interconnects the final point of detour to the destination, or to an original route.
The user can specify the final point of the detour and, hence, can arbitrarily set an alternative path.
Preferably, the route link operation further includes:
a detour check operation which, by comparison, checks whether or not a match exists between the final point of detour and the original route;
a selection operation which, when the route check operation has detected no match, determines whether to search for a new route interconnecting the final point of detour to the destination, or to search for a route which returns the vehicle to the original route, in accordance with settings made by the user;
a new-route search operation which, when the selection operation has determined to search for a new route to the destination, searches for a new route interconnecting the final point of detour to the destination; and
a route return operation which, when the selection operation has selected return of the vehicle to the original route, searches for a route that returns the vehicle from the final point of detour to the original route.
According to the present invention, the user can determine whether to search for a new route interconnecting the final point of detour to a destination, or to search for a route which returns the vehicle to the original route. The user can set either alternative path in accordance with user""s desire.
The present invention also provides a recording medium, such as a computer readable medium, having recorded thereon a processing program for use with a vehicle-mounted navigation system which detects the current position of a vehicle, searches for a route to a set destination, and guides the vehicle along the thus-retrieved route, the processing program including:
a detour check operation which, by comparison, checks whether or not a match exists between the final point of detour and the original route;
a selection operation which, when the route check operation has detected no match, determines whether to search for a new route interconnecting the final point of detour to the destination, or to search for a route which returns the vehicle to the original route, in accordance with settings made by the user;
a new-route search operation which, when the selection operation has determined to search for a new route to the destination, searches for a new route interconnecting the final point of detour to the destination; and
a route return operation which, when the selection operation has selected return of the vehicle to the original route, searches for a route that returns the vehicle from the final point of detour to the original route.
According to the present invention, when the vehicle deviates from the original route, the user can determine whether to search for a new route interconnecting the current position to the destination, or to search for a route which returns the vehicle to the original route. The user can set either alternative path in accordance with the user""s desire.